Researchers from the Institute of Physics of Materials of the Czech Academy of Sciences — Hynek Hadraba, Zdeněk Chlup, and Filip Šiška — have contributed to an international study offering the first detailed ethno-archaeological insights into the heat treatment of lithic raw materials, as practised by traditional artisans from the Konso ethnic group in southern Ethiopia — the last known community still actively using this ancient technology.
The study, published in the prestigious Scientific Reports journal from the Nature portfolio, focuses on mapping the motivations, methods, and material transformations associated with this process. The research revealed that heat treatment of chalcedony, conducted through precise temperature control in covered pits followed by gradual cooling, significantly enhances the stone’s properties, reducing its hardness and fracture toughness, increasing its elasticity and homogeneity, and creating a glossy surface ideal for tool knapping. These findings are crucial for understanding how similar techniques may have been employed in prehistory.
By combining ethnographic observation with advanced analytical methods (including FTIR spectroscopy, confocal microscopy, and mechanical testing), the study provides a novel perspective on the complexity of a technology that has so far been primarily explored through experimental archaeology. It demonstrates that the traditional knowledge of Konso artisans incorporates sophisticated thermal engineering practices that greatly improve tool production efficiency and offer a valuable model for interpreting archaeological findings.
The research is the result of international collaboration between the University of Cape Town, Arba Minch University, Palacký University Olomouc, the Institute of Physics of Materials (CAS), the University of Bordeaux, the University of Florida, and the University of South Florida. Scientific Reports (Impact Factor = 3.8) is a fully open-access journal ranked in the top quartile (Q1) in its field.
